Learn Turkish: Kırk yedi hemşire şimdi hazır mı? - Are forty-seven nurses ready now?

It is very straightforward! Just put the tens word and the ones word together with a space in between. Here, we use kırk (forty) and yedi (seven) to make kırk yedi. You do not need a word for "and" between them.

Why isn't the word for nurse plural (hemşireler) since there are forty-seven of them?

In Turkish, whenever you use a number before a noun to state a specific quantity, the noun must stay in its singular form. You say kırk yedi hemşire (literally "forty-seven nurse"), never kırk yedi hemşireler.

Where is the word for "are" in this sentence?

There is no separate word for "are". In the Turkish present tense, the "to be" verb for third-person subjects (like "he", "she", "it", or "they") is usually implied. Simply placing the question particle mı after the adjective hazır (ready) is enough to mean "Are they ready?".

Why is the question particle mı written as a separate word, and why does it use an "ı"?

Question particles in Turkish are always written with a space before them. It uses an ı because it follows 4-way vowel harmony. The last vowel in the word right before it (hazır) is an ı, so the particle must match it and become mı.